The Molecular Pathogenesis of Infectious Diseases is an area of great interest to an interdepartmental group of 19 faculty members at the University of Colorado Health Sciences Center. This is a newly emerging area for research that encompasses molecular biological and biochemical studies on microbial virulence factors, host resistance mechanisms, regulation of gene expression during infection, structure-function analysis of microbial and host cell molecules that play key roles in infections, analysis of interactions of bacteria and viruses with differentiated host cells in vitro, and studies on infections with genetically modified bacteria and viruses in genetically modified animal models. Our faculty group has a proven record of innovative research in this area. The faculty are training 21 predoctoral students in the multidisciplinary approaches needed to understand and eventually control infectious diseases. Predoctoral students to be supported by the Molecular Pathogenesis of Infectious Diseases Graduate Student Training Grant will learn to identify and solve important research problems in medical microbiology, molecular structure, cellular interactions with bacteria and viruses, and in vivo analysis of bacterial and viral diseases. Highly qualified predoctoral students at the University of Colorado School of Medicine who are doing research on the molecular pathogenesis of bacterial or viral diseases with NIH-funded mentors on the training grant faculty will be selected for appointment to the training grant after they have completed all of their required courses, passed their preliminary and comprehensive examinations, and begun their dissertation research. We request 4 predoctoral student positions for the first year of the grant, 5 for the second year, and 6 for each successive year. Each selected student will be supported by the training grant for a minimum of 2 years during the period of dissertation research. A comprehensive program of seminars, journal clubs, and research-in-progress meetings will train the students to identify important research questions, design well-controlled experiments using a wide variety of molecular, cellular and in vivo techniques, and critically evaluate and present the results. Training in scientific communication skills and ethics in research are important components of the program. The breadth of this integrated, interdepartmental training program will prepare the students well for careers in innovative research and teaching in academia or biotechnology in the important area of the pathogenesis of infectious diseases.